What is the difference between Grid Tied Inverter and Off Grid or regular inverter?

Basically, inverter converts the DC (Direct Current) power source into AC (Alternating Current). Grid Tie Inverters also known as GTI are inverters that you can connect directly to the power outlet. Yes, your house will have two diffrent power sources, and it will not explode. There's a microcontroller inside that synchonizes the generated power to the grid. You cannot do that in regular or Off Grid Inverters. If you will connect the Off Grid Inverter to the grid lines, the inverter will be DAMAGED and might cause injuriies and fire because it is not designed to sync the generated power to the grid. Hybrid Off Grid Inverters (HOG) also known as Grid Tie Inverters with battery backup are simply a combination of GTI and Off-Grid Inverters. Here's the differences between these 3 types of inverters

Grid Tied
Inverter

Off Grid
Inverter

Hybrid
Off Grid Inverter

AC In

Yes

None

Yes*

AC Out

None

Yes

Yes*

Grid power is required for grid synchronization

Yes

No

Yes

Shuts down when the grid is down

Yes

No

No**

Anti-Islanding Protection

Yes

No

Yes

Energizes loads during grid failure (black out)

No

Yes

No

Connected directly to the power outlet

Yes

No

Yes (AC In or AC Terminal)

Feeds all generated power to the grid line

Yes

No

No (Feeds surplus power only)

Local electric company buys excess or surplus power

Yes

No

Yes

Overload Protection

No

Yes

Yes**

Inverter Cost

High

Low

Very High

Full Setup Cost

Low

Very High

High

Grid Billing

Yes

None

Yes

* Connect the AC In or AC Terminal to the power outlet or grid line while AC Out on your appliances
** Critical loads only